DSL terminal-exchange device connecting system and method

ABSTRACT

A DSL  5  is connected between an exchange device  3  and an IAD 1  to which DSL subscriber terminals  2 - 1  through  2 -n are connected, and the exchange device  3  is equipped with a VMG  4  for terminating an ATM cell multiplexed over the DSL  5,  a voice packet transmitted as multiplexed over the DSL  5  is directly terminated at the exchange device  3,  which in turn converts the voice packet into a packet according to an existing exchange device interface  8,  so that DSL subscribers can be accommodated in the exchange device  3  directly and also exchange device software for operating the exchange device  3  can control call processing without knowing about a device under the control of a subscriber control unit, as a result, user burdens can be mitigated.  
     The invention may be embodied in other specific forms without departing from the spirit or essential characteristic thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and rage of equivalency of the claims are therefore intended to be embraced therein.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a DSL terminal-An exchangedevice connecting system and method and, more particularly to, such theDSL terminal-the exchange device connecting system and method that usesa VoDSL technology to transfer voice data in a packet through a DSL.

[0003] 2. Description of the Related Art

[0004] A communication technology for creating an ATM cell by using asubscriber access device is disclosed in Japanese Patent ApplicationLaid-Open No. Hei 11-331191. The VoDSL (Voice over DSL) technology canbe used in a voice communication service. In a voice communicationservice by use of VoDSL, a subscriber using the VoDSL technology isaccommodated in a exchange device 101 by, as shown in FIG. 4,terminating voice data transmitted in an ATM cell through an xDSL 102with a VoDSLGW (gateway) 103 and utilizing an access network such as aV5 or GR-303 interface 104. To apply the voice communication service byuse of the VoDSL technology to the existing exchange device 101, it isnecessary to prepare a switching device for connecting such an accessnetwork 104 into the exchange device 101. The connection of the line andthe installation of such a switching device will result in thecorresponding costs being imposed on an end user.

[0005] However, it is desired to avoid increasing such costs.

SUMMARY OF THE INVENTION

[0006] It is an object of the present invention to provide such a DSLterminal exchange device connecting system and method that will notincrease the costs on a user.

[0007] Means for solving this problem is expressed as follows.Technological items given in this expression are assigned a subscript ofa numeral, a symbol, etc. parenthesized. These numeral, symbol, etc.agree with those added to technological items which constitute at leastone or a plurality of embodiments or examples of the present invention,in particular such technological items that are given in drawings whichcorrespond to these embodiments or examples. Those reference numeralsand symbols are given to clearly define the correspondence orcorrelation between the technological items described in the claims andthose described in the embodiments or examples. Such correspondence orcorrelation does not mean that the technological items described in theclaims are limited to those described in the embodiments or examples.

[0008] A DSL terminal-An Exchange device connecting system according topresent invention comprising: the exchange device 3; a DSL subscriberterminal 2-n; an IAD 1 to which said DSL subscriber terminal 2-n isconnected; and a DSL 5 interposed between said exchange device 3 andsaid IAD 1, wherein said exchange device 3 having a VMG 4 forterminating an ATM cell which is multiplexed on said DSL 5.

[0009] Call processing can be controlled without knowing about a deviceunder the control of a subscriber control unit by the exchange devicesoftware that can terminate a voice packet transmitted as multiplexedover a DSL (5) by using the exchange device (3), which then converts thevoice packet into a packet according to an existing exchange deviceinterface to thereby directly accommodate a DSL subscriber therein.

[0010] Since voice data over the xDSL utilizing the VoDSL technology isthus converted into data according to the existing exchange deviceinterface data directly, the DSL subscriber appears to the exchangedevice to be equivalent to an existing voice communication servicesubscriber and so can be accommodated in an existing exchange device. Itis, therefore, possible to increase the number of subscribers who can beaccommodated in the exchange device only by providing the exchangedevice with a VMG (Voice Media Gateway) just like a subscriberaccommodating device, thus decreasing the equipment funds foraccommodation of the subscribers. By replacing an existing subscriberaccommodating device with a VMG in a remote station installed in aremote area also, it is possible to increase the number of subscribersaccommodated by that remote station.

[0011] The VMG(4) can be equipped with a DSL•IF terminating unit (7) fordirectly terminating an ATM cell to thereby terminate the ATM cell atthe exchange device. The VMG(4) further including an AAL processing unit(9) for dividing the ATM cells terminated at the DSL•IF terminating unit(7)to a voice signal cell (11) and a call control signal cell (12), aDSP (13) for converting an ADPCM data for the voice signal cell (11),and a MUX/DMUX (14) for multiplexing the voice signal cell converted bythe DSP(13) and the call control signal cell (17). Thus added DSP isadapted to convert voice data from, for example, 32KADPCM to 64KADPCM inmodulation data. A DSLAM (Digital Subscriber Line Access Multiplexer)(21) can be terminated at a DSL (5) to thereby convert voice on the DSL(5) into an ATM cell. The DSLAM (21) can be directly connected to theAAL (9) through an ATM network (22), in which case the DSL•IFterminating unit (7) is omitted.

[0012] A method of present invention for connecting the exchange devicefor a DSL terminal comprises the steps of terminating at the exchangedevice (3) a voice packet transmitted as multiplexed over the DSL (5)and permitting the switchboard (3) to convert the voice packet into apacket according to an existing switchboard interface (8), thus enablingdirectly accommodating a subscriber in the exchange device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is system block diagram for showing a DSL terminal-exchangedevice connecting system according to an embodiment of the presentinvention;

[0014]FIG. 2 is a circuit block diagram for showing details of part ofFIG. 1;

[0015]FIG. 3 is a system block diagram for showing the DSLterminal-exchange device switchboard connecting system according toanother embodiment of the present invention; and

[0016]FIG. 4 is a system block diagram for showing a publicly knownVoDSL communication system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] A DSL terminal—An exchange device connecting system according toan embodiment of the present invention comprises a exchange device aswell as an IAD (Integrated Access Device) as shown in the figures. Asshown in FIG. 1, this IAD 1 is connected with subscriber terminals 2-1through 2-n (n=1 and 2 in the figure) to thereby accommodate them. Theexchange device 3 of the system has a VMG 4 therein. The IAD 1 isconnected to the VMG 4 through an xDSL 5.

[0018] The VMG 4 terminates the xDSL 5 for transferring voice data ofeach of a plurality of telephone subscribers accommodated in the IAD 1.The voice data thus transferred is converted into an ATM cell and thentransferred through the xDSL 5 to the VMG 4 in the IAD 1.

[0019]FIG. 2 shows a detailed internal configuration of the VMG 4. Asshown in FIG. 2, the VMG 4 has an xDSL•IF terminating unit 7 therein.The VMG 4 uses the xDSL•IF terminating unit 7 to terminate the xDSL 5 inorder to extract voice data from the ATM cell transferred over the xDSL5 and multiplex it at a subscriber control device interface 8accompanying the VMG 4. Thus multiplexed voice data is transferred to asubscriber control unit (LOC) 6.

[0020] An ATM component received and extracted at the xDSL•IFterminating unit 7 is transferred to an AAL processing unit 9. This ATMcomponent undergoes SAR processing at the AAL processing unit, fromwhich a voice signal cell 11 and a call control signal 12 are divided.The voice signal cell 11 may sometimes be compressed with such acompressing technology as a 32K ADPCM data so that the voice data mayenhance an accommodating efficiency of the xDSL 5 thereon.

[0021] The voice signal cell 11, if compressed in such a manner, dividedat the AAL processing unit 9 to then be transferred to a DSP13. Thevoice signal cell 11 is converted at the DSP 13 from 32K ADPCM to 64KADPCM in modulation data and transferred to a MUX/DMUX 14.

[0022] The call control signal 12 that otherwise divided at the AALprocessing unit 9 is output from there to be read out by a CPU 15. TheAAL processing unit 9 is connected to the CPU 15 through a CPU bus 16.The CPU 15 analyzes call control information of the call control signal12 and interprets it into exchange device control data 17. The exchangedevice control data 17 is written through the CPU bus 16 into an SG•CTL18.

[0023] The SG•CTL 18 converts the exchange device control data 17 intodata of a subscriber control interface format and then transfers it tothe MUX/DMUX 14. The MUX/DMUX 14 in turn transfers thus multiplexedvoice signal 11 and the call control signal 12 to the subscriber controlunit 6 through the subscriber control device interface 8. The voice dataat the subscriber control unit 6 is transferred back to the IAD 1 byperforming reverse transferring as against the above-mentionedtransferring and inverted multiplexing as against the above-mentionedmultiplexing.

[0024]FIG. 3 shows an other embodiment of exchange device connectingsystem of DSL terminal according to present invention. As shown in FIG.3, this embodiment of the present invention utilizes an ATM network.This ATM network 22 is connected using lines between the IAD 1 and a VMG4′ in the exchange device 3. Between the ATM network 22 and the IAD 1, aDSLAM 21 is provided to the xDSL 5. The xDSL 5 is terminated at theDSLAM 21 to be then converted into an ATM interface 23. The xDSL•IFterminating unit 7 of FIG. 2 is omitted in the VMG 4′ in the exchangedevice 3 according to this embodiment. The ATM interface 23 isterminated at the AAL processing unit 9 of the VMG 4 of FIG. 2, in whichthe xDSL•IF terminating unit 7 is omitted.

[0025] Thus, the DSL terminal-exchange device connecting system andmethod of the present invention employs a direct accommodating method,thus enabling mitigating the user burdens.

[0026] The invention may be embodied in other specific forms withoutdeparting from the spirit or essential characteristic thereof. Thepresent embodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

[0027] The entire disclosure of Japanese Patent Application No.2001-29601 (Filed on Feb. 6, 2001) including specification, claims,drawings and summary are incorporated herein by reference in itsentirety.

What is claimed is:
 1. A DSL terminal-An Exchange device connectingsystem comprising: the exchange device; a DSL subscriber terminal; anIAD to which said DSL subscriber terminal is connected; and a DSLinterposed between said exchange device and said IAD, wherein saidexchange device having a VMG for terminating an ATM cell which ismultiplexed on said DSL.
 2. The DSL terminal-An Exchange deviceconnecting system according to claim 1, wherein said VMG including aDSL•IF terminating unit for terminating said ATM cell directly.
 3. TheDSL terminal-An Exchange device connecting system according to claim 2,wherein said VMG further comprises: an AAL processing unit for dividingsaid ATM cells terminated at said DSL•IF terminating unit to a voicesignal cell and a call control cell; a DSP for converting an ADPCM dataof said voice signal cell; and a MUX/DMUX for multiplexing said voicesignal cell converted by said DSP and said call control signal cell. 4.The DSL terminal switchboard connecting system according to claim 3,wherein said DSP converts said voice signal cell from a 32KADPCM data toa 64KADPCM data.
 5. The DSL terminal-An exchange device connectingsystem according to claim 3, further comprising a DSLAM which isterminated at said DSL to thereby convert voice over said DSL into theATM cell, said DSLAM being connected to said AAL processing unit throughan ATM network.
 6. A DSL terminal-An exchange device connecting methodcomprising the steps of: terminating at an exchange device a voicepacket transmitted as multiplexed over a DSL; and converting at saidexchange device said voice packet into a packet according to an existingexchange device interface.